So theoretically I could build a wrapper type for Unsafe(Mutable)Pointer which will be safe to use and never exceed the allocated range!
public func successor() -> UnsafeMutablePointer<Memory>? { // return `nil` if out of range } So why don’t we have safe pointers today? Any technical reasons or do I miss something here?! -- Adrian Zubarev Sent with Airmail Am 26. Mai 2016 bei 19:14:41, Andrew Trick (atr...@apple.com) schrieb: On May 26, 2016, at 9:59 AM, Adrian Zubarev via swift-users <swift-users@swift.org> wrote: I’ve got one more questions about Unsafe(Mutable)Pointer. I know that I’m able to access memory that might not belong to me. My question is: Can I trust these functions that they will return a pointer to some memory when I allocate more than one object AND when I’m moving only inside that range? Yes. public func successor() -> UnsafeMutablePointer<Memory> public func predecessor() -> UnsafeMutablePointer<Memory> public func advancedBy(n: Int) -> UnsafeMutablePointer<Memory> UnsafeMutablePointer<Int>.alloc(4) when I advance only in range of [0,1,2,3] am I safe or could I get a pointer to memory that does not belong to me? UnsafeMutablePointer<T>.alloc(N) creates a single object in memory that holds N consecutive T values. Each value resides at index*strideof(T.self) bytes beyond the allocated pointer where index is valid in the range 0..<N. -Andy Example: // imagine this is some memory portion, // where x is memory that does not belong to me // and 0 is moemory free to use […, x, 0, 0, 0 x, 0, x, …] // now I want to allocate 4 objects // variant A: […, x, MY1, MY2, MY3, x, MY4, x, …] // my pointer will sit at `MY1` and if I advance by 2 I'll get `x` // can this happen to me? // variant B: // Unsafe(Mutable)Pointer will ensure that I always get memory tied together // (or the above functions will skip memory that doesn't belong to me??): […, x, MY1, MY2, MY3, MY4 x, …] So which is right? -- Adrian Zubarev Sent with Airmail _______________________________________________ swift-users mailing list swift-users@swift.org https://lists.swift.org/mailman/listinfo/swift-users
_______________________________________________ swift-users mailing list swift-users@swift.org https://lists.swift.org/mailman/listinfo/swift-users